1. Field of the Invention
The present invention relates to a cooling/heating dual-purpose air conditioner, and more particularly to an accumulator construcation of a cooling/heating dual-purpose air conditioner for preventing a liquid refrigerant from flowing into a compressor resulting from a lack of heat source in accordance with a decrease of outside temperature during a heating, and at the same time for achieving a smooth retrieval of oil.
2. Description of the Prior Art
Generally, a cooling/heating dual-purpose air conditioner performs a continuous process of compression, condensation, expansion and evaporation to thereby achieve a heating or performs the above process reversely to thereby achieve a cooling or defrosting.
FIG. 5 depicts a refrigerant cycle in a conventional air conditioner.
In FIG. 5, a high-temperature and high-pressure refrigerant compressed at a compressor 1 is inflowed into an indoor heat exchange 4 through a four-way valve 2 during the heating.
A condensation reaction is realized in the high-temperature, high-pressure refrigerant inflowed into the indoor heat exchange 4 by a static pressure transfer.
The refrigerant condensed at the indoor heat exchange 4 passes sequentially through pressure reducers 6 and 8 to thereby be adiabatically expanded.
The refrigerant adiabatically expanded at the pressure reducers 6 and 8 is induced into an outdoor heat exchanger 3 to thereby be evaporated by a static pressure heat transfer.
The refrigerant drained from the outdoor heat exchanger 3 passes sequentialy through accumulators 12 and 13 via the four-way valve 2 and only the evaporated refrigerant is re-induced into the compressor 1.
Meanwhile, a refrigerant cycle reversed from the above cycle is performed during the cooling and defrosting.
The four-way valve 2 sends the refrigerant from the compressor 1 to the indoor heat exchanger 4 during the heating, and during the cooling and defrosting, the refrigerant from the compressor 1 is sent to the outdoor heat exchanger 3.
Meanwhile, a reference numeral 7 is a nonreturn valve which passes the refrigerant during the cooling and checks the refrigerant during the heating.
In the refrigerant cycle thus constructed, the refrigerant gas is supposed to be inflowed into the compressor 1 as a perfect gaseous refrigerant after the refrigerant gas is heat-exchanged at the outdoor heat exchanger 3, however because a perfect heat exchange can not be realized when the outdoor temperature is very low (generally below 3 degrees Celsius) due to the lack of heat source, some portions of the liquefied refrigerant gas which has yet to be heat-exchanged are induced into the compressor 1 along with the gaseous refrigerant to thereby downgrade an efficiency of the compressor.
In the words, when the liquefied refrigerant is introduced into the compressor 1, there occurs a hydraulic compression phenomenon wherein non-compressive liquid changes instantly to gaseous material to thereby increase a cubic volume of refrigerant, so that damage to the compressor and a diminishing of its efficiency may result.
Accordingly, accumulators 12 and 13 are used in series on a refrigerant pipe interconnecting the outdoor heat exchanger 3 and the compressor 1 in order to completely separate the liquified refrigerant contained in the gaseous refrigerent.
FIG. 6 is a constitutional diagram of accumulator installations 12 and 13 in the conventional cooling/heating dual-purpose air conditioner as illustrated in FIG. 5.
In FIG. 6, the refrigerent inflowed into the first accumulator 12 passes through a hole 18a formed on a baffle plate 18 and the gaseous refrigerant is inflowed into the second accumulator 13 through a stand pipe 20.
Meanwhile, oil is injected into the compressor in order to smooth off the operation of the compressor 1 and at this moment, the oil is mixed with the refrigerant in the compressor 1 to thereby be discharged.
The oil flows to the bottom of the first accumulator 12 through the hole 18a formed on the baffle plate 18 to thereby flow into the stand pipe 20 through an oil return hole 20a.
The refrigerant mixed with the compressor oil thus explained is flowed into the second accumulator 13 to thereby be filtered at a filtering mesh 22.
The refrigerant whose impurities have been filtered off at the filtering mesh 22 passes through a hole 24a of the baffle plate 24 and gaseous refrigerant is flowed into the compressor 1 through a stand pipe 26.
The compressor oil that has passed the hole 24a of the buffle plate 24 flows to the bottom of the second accumulator 13 to thereby be retrieved by the compressor 1 through the oil return hole 26a.
Here, the buffle plates 18 or 24 are formed with a plurality of holes a,b,c and d as illustrated in FIG. 7, and the center of the baffle plate 18 or 24 where the stand pipe 20 or 26 is disposed protrudes upwardly and the holes a,b,c and d are formed around a periphery of the respective protrusions.
Accordingly, the gaseous refrigerant that has passed through a plurality of holes formed on the baffle plate 18 or 24 is flowed into the stand pipe 20 or 26, and the liquid refrigerant flows toward the bottoms of the first and second accumulators 12 and 13 to thereby be accumulated, so that only the gaseous refrigerant can be flowed into the compressor 1.
When the liquefied refrigerant which has not evaporated the outdoor heat exchanger 3 due to low outdoor temperature is accumulated at the bottom of the first accumulator 12 or second accumulator 13, the above-mentioned lubricating oil is separated to thereby float on a surface of the liquified refrigerant.
Therefore, the oil might not be retrieved through the oil return holes 20a or 26a, so that the compressor 1 cannot smoothly be operated.
Furthermore, because a plurality of accumulators are connected in series to prevent the liquefied refrigerant from flowing into the compressor, a problem arises in that an installation calls for a large space, so that construction gets complicated and an efficiency decreases due to a pressure drop resulting from a dual expansion.